1. Preheat oven to 175-210 ° C.
2. In a large bowl, mix together the buttermilk, eggs, melted butter, sugar, 1 tbsp vanilla (until the sugar is dissolved).
3. Add the baking powder, salt, sifted flour and mix well.
4. Divide the dough into 7 pieces and put in different containers.
5. Add color different dyes in separate parts of the dough and mixed.
6. Transfer the colored pieces of dough in pastry bags.
7. Coat the molds with oil to donuts (or place the parchment on a baking sheet).
8. squeeze out a drop of each color in a circle, in accordance with the sequence of arrangement of colors in the rainbow (or your own order).
9. Bake for 4-8 minutes or until the top of the springiness when pressure on it.
10. Without removing from the molds or baking, allow to cool for 4-5 minutes.
11. For the glaze, mix the icing sugar with the milk and vanilla. You can spread it our mini-donuts.
12. Or simply pour into a beautiful kremanku decorate confectionery grit and dipping in her donuts.